Moving Tree Swallows:
First, let me state, Tree Swallows are usually only a problem with SMALL single house or NEW martin colonies. Although beautiful, they are a tenacious little bird and will defend their area at all costs. However; larger established martin colonies are usually able to hold their own against Tree Swallows unless they have absolutely no where else to nest, so simply supply them some housing that they prefer and there's no problem from them at all.
Every once in awhile, Tree Swallows will get established in martin houses and if this happens, of course, the Tree Swallows, as is their nature, defend the house from ALL other swallows and this includes Purple Martins. So, what do we do if this happens? Easy!
We move them!
Believe it or not, it's rather easy to move Tree Swallows. Here's how!
Now, how you move them depends on what type of housing you have, houses or gourds. Each has a slight difference in the way it's done.
So, we'll attack moving them from a house, first.
Since they're in a house, you'll have to acquire some similar type housing. Personally, I like the little Bluebird/Tree Swallow house called a BB Villa that is sold by S&K Mfg out of O'Fallon, Missouri. I have a lot of them on my Bluebird trail and the Tree Swallows just love them. They have an extra bracket that mounts to them and fits on a T-pole very nicely. I then placed the T-pole off to the side of my colony site where I wanted to put them. Now I was ready to move them. It takes a couple days to make the move, so be patient, it's well worth it.
Tree Swallows are a little more 'snippier' than martins and you might get buzzed, but don't let it bother you. They won't hurt you. They're just trying to defend their nest.
The following are the details of what is needed to move Tree Swallows.
Take the BB Villa (or Bluebird house) and very carefully remove the nest in its entirety from the house and set it in the back corner of the BB Villa. BB Villa's have a large inspection port on them making this very easy. If it's just a Bluebird house, then simply set it in the bottom of the box. Since all martin houses are somewhat different, it might take a little work, (I use some wire and Duct tape) but temporarily attach it to the house directly over the entrance they were using. As can be seen in the photos, TS love feathers in their nests and will search far and wide for them, so simply take one of the softer looking white feathers they used in the nest and stick it in the entrance of the new compartment. Now sit back and let them find and accept the new housing.
Lower the house and again, let them find and accept the house.
Stick the T-pole in the ground, attach the BB Villa to it and then raise the house back up, closing off all holes of the martin house. Again, let them start using the new house.
Obviously, if you already have martins in your house, DO NOT close off the holes they are using, otherwise, they won't be able to get in.
Move the T-post half-way towards its final destination and set the the BB Villa on it. Again, stick a feather from the nest in the opening and a couple more on the ground right in front of it. One or two is all that's needed.
Now, finally move the T-post to its final destination and insure that the entrance of the BB Villa is facing your house so you can watch them. Again do the thing with the feathers, a soft fluffy one in the hole and one or two on the ground in front of it.
Now, you can open up your martin house and you've successfully moved your Tree Swallows and they will leave your martin house alone.
Moving them from a gourd rack:
This is a little easier. What you'll need is a Shepard's Hook and an extra gourd.
Since they're already in the gourd, all you have to do is move the gourd in its entirety, nest and all.
Simply lower the rack, stick the Shepard's Hook in the ground and attach the gourd to the Shepard's Hook in the exact same place it would be as if on the rack. Leave the rack down and let them find their gourd again and spend the night.
Raise the rack, leaving the Shepard's Hook in place.
Move the Shepard's Hook half-way to the intended final destination. Take a couple of feathers from the nest, stick one in the entrance hole and one on the ground right in front of it. They'll find it and let them spend the night.
Move the Shepard's Hook to its final destination. Again, repeat with the feathers.
Now you can replace the gourd on the rack and the Tree Swallows will leave it alone.
And there you have it, you've moved your Tree Swallows.
If their gourd or BB Villa is put in the same place the following year, many times they will return right to it and will not give you any trouble in the martin colony. However, if they (or another pair) do decide to move into another gourd on the rack, the same procedure can be followed each time and you can have both species nesting in your yard. Once one pair of TS takes up nesting, they will keep all other TS out of the immediate area, so you only have to deal with one pair around your racks. No, they will not let another pair settle in your racks or house, they will drive them away.
However; if you have Bluebirds in the area, I suggest putting some housing up for them as well, otherwise, you'll run into the same problems with them because they are looking for housing as well, but if their housing is already available, they won't bother your martin housing.
Here's a Little Tip...
If you do order a BB Villa, don't forget the little bracket that's used specifically for mounting BB boxes to T-shaped fence posts. It can be purchased from S&K Manufacturing along with the BB Villa. Or if you already have your own housing and would like to order the T-Post Mount bracket alone (TPM), then do that. They are rather inexpensive, so you might want to consider getting a couple... just in case...
I presently have a BB trial along the road that I live on that is 1 1/2 miles long and has 36 boxes (both wood and plastic) on it. Just about every box is mounted to a T-post using one of these little TPM brackets. Very easy to install and they work beautifully. If the boxes are near livestock (cows and horses), you might want to add a couple of hose clamps, one above and one below the bracket so that the livestock can't dislodge or upset the box. It also helps prevent the box from being 'lifted' off the post and taken to someone else's back yard.
And one last note:
After they've left for the season, don't just discard their entire nest. Take the time to sort out some of their softer feathers and put them in a Ziploc bag. Then stick them on a shelf somewhere and you'll have a few of these feathers next spring. Then, when you first see them return, sprinkle a couple on the ground in front of their nest box (where you want them), they'll find them and probably move right in and not give you any trouble at all, especially if it's where they successfully nested the previous year.